Optic and assembly for reduced reflections

Abstract

An optic providing reduction in secondary or ghost images includes a beam splitter, a reflective surface, and at least one baffle therebetween. A transmissive surface may be located between the beam splitter and the reflective surface. The baffle is positioned to intercept internally reflected ghost rays while being substantially parallel to outside light rays along a line of sight of the viewer, permitting use in see-through optics. The baffles may be formed of diffusing structures, light absorbing material, and combinations of both. Baffles intercept and scatter or absorb ghost rays to the exclusion of projected image rays that provide a desired projected image which are internally reflected through the optic. An assembly including such optic integrated with a wearable vision system, such as a head-mounted display, is also disclosed for near-eye application.

What is claimed is: 
     
       1. An optic, comprising:
 a beam splitter within said optic configured to (i) receive projected light rays corresponding to a desired projected image to be presented to a user for viewing and a ghost image that obfuscates said desired projected image, and (ii) selectively transmit at least a portion of said projected light rays; 
 a reflective surface within said optic configured to receive said projected light rays transmitted from said beam splitter and reflect said projected light rays inwardly to said beam splitter; and 
 at least one baffle having a diffusing structure with surface irregularities configured to scatter said projected light rays corresponding to said ghost image, said at least one baffle disposed within said optic between said beam splitter and said reflective surface, positioned to intercept said projected light rays corresponding to said ghost image from reflection by said reflective surface to said beam splitter. 
 
     
     
       2. The optic as recited in  claim 1 , wherein said optic is a see-through optic. 
     
     
       3. The optic as recited in  claim 1 , wherein said at least one baffle is spaced apart a predetermined distance from said beam splitter and said reflective surface. 
     
     
       4. The optic as recited in  claim 3 , wherein said predetermined distance between said at least one baffle and said reflective surface is based on at least one of: a curvature of said reflective surface, an area of a projected light incident surface receiving said projected light rays, a refractive index of said optic, and a thickness of said optic, wherein said thickness is defined by a distance between a distal surface and an opposite proximal surface of said optic, and wherein said proximal surface of said optic is positioned closer to a viewer when in use. 
     
     
       5. The optic as recited in  claim 3 , wherein said predetermined distance between said at least one baffle and said reflective surface is up to 3 mm. 
     
     
       6. The optic as recited in  claim 1 , wherein said at least one baffle extends inwardly from an exterior surface of said optic. 
     
     
       7. The optic as recited in  claim 1 , wherein said at least one baffle includes a baffle axis defined along a center of said at least one baffle, said at least one baffle positioned so said baffle axis is at an oblique angle or perpendicular angle relative to said projected light rays and substantially parallel to an optical axis defined along a line of sight of a viewer. 
     
     
       8. The optic as recited in  claim 1 , wherein said at least one baffle extends along at least a portion of a width of said optic, wherein said width is defined by a distal surface or a proximal surface of said optic, wherein said proximal surface of said optic is positioned closer to a viewer when in use. 
     
     
       9. The optic as recited in  claim 1 , further comprising a plurality of baffles, wherein a first baffle extends inwardly from a distal surface of said optic and a second baffle extends inwardly from a proximal surface of said optic, wherein said proximal surface of said optic is positioned closer to a viewer when in use. 
     
     
       10. The optic as recited in  claim 1 , wherein said at least one baffle further includes light absorbing material configured to absorb said projected light rays corresponding to said ghost image. 
     
     
       11. The optic as recited in  claim 10 , wherein said light absorbing material is configured to absorb at least 99% of said projected light rays corresponding to said ghost image and is selected from the group consisting of paint, film, and coating. 
     
     
       12. The optic as recited in  claim 11 , wherein said light absorbing material is further configured to selectively absorb predetermined wavelengths of light. 
     
     
       13. The optic as recited in  claim 1 , wherein said projected light rays include (i) image rays corresponding to said desired projected image and (ii) ghost rays corresponding to said ghost image, wherein said at least one baffle is positioned and configured to selectively intercept said ghost rays from reflection by said reflective surface to said beam splitter to the exclusion of said image rays. 
     
     
       14. The optic as recited in  claim 1 , further comprising a transmissive surface positioned between said beam splitter and said reflective surface and configured to transmit said projected light rays. 
     
     
       15. The optic as recited in  claim 14 , wherein said beam splitter is a polarizing beam splitter configured to reflect said projected light rays of a first polarization and transmit said projected light rays of a second polarization, and further comprising a polarizing surface at said transmissive surface, said polarizing surface configured to rotate said projected light rays of said second polarization when passing therethrough. 
     
     
       16. An assembly comprising said optic as recited in  claim 1  and a vision system configured to position said optic along an optical axis defined by a line of sight of a viewer. 
     
     
       17. The assembly as recited in  claim 16 , wherein said vision system is one of glasses, sunglasses, safety glasses, goggles, visor, and helmet. 
     
     
       18. The assembly as recited in  claim 16 , further comprising an image source configured to project said projected light rays to a projected light incident surface of said optic, and a housing configured to retain said optic and said image source in fixed relation relative to one another. 
     
     
       19. The assembly as recited in  claim 18 , further comprising a mounting unit configured to attach said housing to said vision system. 
     
     
       20. The assembly as recited in  claim 19 , wherein said mounting unit is configured to selectively attach said housing to said vision system. 
     
     
       21. The assembly as recited in  claim 19 , wherein said mounting unit is selectively adjustable to position said housing between (i) an operative mode where said optic is aligned with said optical axis and (ii) an inoperative mode where said optic is misaligned with said optical axis. 
     
     
       22. The assembly as recited in  claim 19 , wherein said vision system includes a frame and said mounting unit is attachable to said frame. 
     
     
       23. The assembly as recited in  claim 18 , further comprising a control unit in electrical communication with said image source, said control unit having a processor and configured to provide at least one image to said image source to project said projected light rays corresponding to said at least one image. 
     
     
       24. The assembly as recited in  claim 23 , further comprising a user interface in electrical communication with said control unit configured to receive input from a user corresponding to selection of said at least one image, said processor of said control unit further configured to receive said input from said user interface.